C0549423
Obstructive Hydrocephalus
Concept
CUIC0549423
PreferredObstructive Hydrocephalus
Cross-maps
SNOMED230746009
SNOMED82346000
ICD-10G91.1
ICD-10MTHU035904
ICD-10MTHU035906
ICD-10MTHU053253
ICD-10MTHU053838
ICD-118D64.1Z
Source vocabularies
Atoms not loaded for this concept.
# same page, as API
GET autoicdapi.com/api/v1/reference/umls/C0549423
GET autoicdapi.com/api/v1/translate?code=C0549423&from=umls&to=snomed-ct
Common questions
What is the UMLS CUI for Obstructive Hydrocephalus?
Obstructive Hydrocephalus is coded as C0549423 in UMLS.
What is UMLS code C0549423?
C0549423 is the UMLS identifier for Obstructive Hydrocephalus. It is included in the current NLM UMLS Metathesaurus release.
What is the ICD-10-CM mapping for C0549423?
C0549423 maps to 5 ICD-10-CM codes (G91.1, MTHU035904, MTHU035906, MTHU053253, MTHU053838).
What is the ICD-11 mapping for C0549423?
C0549423 maps to ICD-11 8D64.1Z.
UMLS, plainly answered
What is UMLS?
The Unified Medical Language System is the NLM's meta-terminology that unifies SNOMED CT, ICD-10, ICD-11, RxNorm, LOINC, MeSH, and around 200 other source vocabularies under a single concept identifier (CUI). One UMLS CUI can group dozens of synonymous codes from different terminologies.
What is a CUI and why does it matter?
A CUI is a stable identifier (like C0011860) that points at a single clinical idea regardless of how that idea is encoded in any specific vocabulary. CUIs are the most reliable way to bridge between terminologies when you need to compare or merge data from multiple sources.
How does UMLS help with cross-mapping?
Every UMLS concept page lists the codes it groups together. That gives you a free crosswalk: a SNOMED concept and an ICD-10 code that share a CUI describe the same clinical idea. Our cross_references API returns these groupings inline.
Is the API free to use?
Browsing the directory is free. Programmatic /api/v1/reference/umls/* access needs an API key. Production volume requires a paid tier.
How fresh is the UMLS data?
We track NLM's twice-yearly releases (May AB and November AB). Each release brings new concepts, retirements, and atom updates from the source vocabularies, and our index reflects them within the same week.
Do I need a UMLS license?
Yes. The UMLS Metathesaurus License Agreement is free but requires an NLM UTS account. Customers in production need their own license. Free-tier evaluation use is permitted under the standard terms.